Bug 81657 fix merge to 5.6 broken

[Laurynas Biveinis]

Copy of

http://bugs.mysql.com/bug.php?id=83124:

[23 Sep 9:24] Laurynas Biveinis
Description:
Bug 81657 fix in 5.5 introduced get_locked_tables_mode_name helped function and called it from THD::decide_logging_format.

The way this was merged to 5.6, the new helper function is introduced, but it's never called, and THD::decide_logging_format still contains the following:

#ifndef DBUG_OFF
    {
      static const char *prelocked_mode_name[] = {
        "NON_PRELOCKED",
        "PRELOCKED",
        "PRELOCKED_UNDER_LOCK_TABLES",
      };
      DBUG_PRINT("debug", ("prelocked_mode: %s",
                           prelocked_mode_name[locked_tables_mode]));
    }
#endif

[Laurynas Biveinis (laurynas-biveinis)]

https://github.com/percona/percona-server/pull/1066
https://github.com/percona/percona-server/pull/1067

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PS-1750